Electrically conductive crown architecture for a tire of a heavy duty civil engineering vehicle

A tire for heavy vehicle of construction plant type comprising:

• a tread comprising two axial end portions or tread wings axially separated by a central portion;
• a base layer, radially on the inside of the tread, comprising at least one lateral portion at least partly in contact with the tread wing;
• a crown reinforcement, radially on the inside of the base layer, comprising at least one crown layer, having metallic reinforcers that are coated in an electrically-conductive elastomeric compound;
• two sidewalls in contact at least partly with the tread wings connecting the tread wings to two beads, adapted to come into contact with a mounting rim by means of a bead layer made of electrically-conductive elastomeric compound;
• each said sidewall being axially on the outside of a carcass reinforcement comprising at least one carcass layer having metallic reinforcers that are coated in an electrically-conductive elastomeric coating compound;
• at least one tread wing having a first elastomeric compound M1 having a thermal conductivity λ1 and an electrical resistivity ρ1;
• the central tread portion having a second elastomeric compound M2 having a viscoelastic loss tgδ2;
• the base layer having a third elastomeric compound M3 having a thermal conductivity λ3 and an electrical resistivity ρ3;
• each said sidewall having a fourth elastomeric compound M4 having a viscous dynamic shear modulus G″4,
• wherein the first elastomeric compound M1 of at least one said tread wing has a thermal conductivity λ1 at least equal to 0.190 W/m·K, wherein the second elastomeric compound M2 of the central tread portion has a viscoelastic loss tgδ2 at most equal to 0.06, wherein the third elastomeric compound M3 of the base layer has a thermal conductivity λ3 less than the thermal conductivity λ1 of the first elastomeric compound M1 of the at least one tread wing, wherein the electrical resistivities ρ1 and ρ3 respectively of the first elastomeric compound M1 and of the third elastomeric compound M3 are at most equal to 106 ′Ω·cm, so that the bead layer, the elastomeric coating compound of the carcass layer, the coating compound of the at least one crown layer, the base layer, and the tread wing constitute a preferential conductive pathway of the electric charges between the rim and the ground when the tire is mounted on its rim and flattened on the ground, and wherein the fourth elastomeric compound M4 of each said sidewall has a viscous dynamic shear modulus G″4 at most equal to 0.125 MPa.